Extending Power and Sample Size Approaches Developed for McNemar's Procedure to General Sign Tests

Current software and textbooks present procedures to estimate power and sample size for sign tests that only apply to settings where positive (i.e., X = 1) or negative (i.e., X =−1), but not neutral (i.e., X = 0) outcomes occur. However, many studies analyzed by sign tests involve the more general setting where significant amounts of neutral outcomes can occur. This paper illustrates extension of existing power/sample size approaches and software that have been developed for matched binary responses (McNemar's discordant pairs) to general sign tests with neutral outcomes occurring. An application is made to a recent study that the author collaborated on.     

美国预约定价的新发展

自1991年开启预约定价以来,美国国税局不断更新自己的预约定价税收程序,最终形成2004-40税收程序,为理论和实务界人士看好.仅过两年,国税局又更新了2004-40税收程序,出台了2006-9税收程序.此次预约定价对美国十几年来的诸多预约定价理念进行了矫正,与纳税人息息相关.代表世界预约定价法发展趋势的美国2006-9税收程序对我国也有不小的冲击,我们应理性看待美国此次预约定价的革新运动,并着手我国的预约定价立法和实践的改革.     

A note on theE-optimality of block designs

Summary In this paper we consider the problem of determiningE-optimal block designs for experimental situations in whichv treatments are to be tested onn experimental units arranged inb blocks and where the block sizes and number of replications assigned to the treatments are allowed to vary. Some sufficient conditions are obtained for designs to beE-optimal in these situations and methods for constructing designs which satisfy the sufficient conditions given are also derived.     

The demand for home mortgage assets by savings and loan associations

The purpose of this article is to analyze empirically the factors that enabled S&Ls to respond, concerning their demand for home mortgage assets, to the record high interest rates, inverted yield curves, and new competition for deposits by money market mutual funds. These factors include changing regulatory accounting procedures, increased participation in the secondary mortgage market, and increased asset diversification allowed for by Garn-St. Germain. The empirical results are based on a model of the demand for home mortgage assets specified in terms of an optimal marginal portfolio adjustment model. The results show that changing regulatory procedures and the subsequent impact on secondary mortgage markets had the most impact. The increased lending power granted by Garn-St. Germain had little effect on the demand for home mortgage assets by S&Ls.     

Cost per responder analysis in patients with secondary hyperparathyroidism on dialysis treated with cinacalcet

Abstract

Background:

Growing financial pressure on US dialysis providers requires economic efficiency considerations. The objective of this study was to examine short-term economic efficiencies of a cinacalcet-based treatment approach for secondary hyperparathyroidism.

Methods:

This study retrospectively assessed cost per biochemical response of the OPTIMA trial. OPTIMA was conducted in end-stage renal disease patients to compare biochemical control in patients receiving cinacalcet in addition to vitamin D sterols and phosphate binders vs patients receiving vitamin D sterol and phosphate binders alone. It explored three laboratory measurement response definitions from baseline to week 23: (1) decreases in parathyroid hormone (PTH) ≥30%; (2) PTH?≤?300?pg/ml; and (3) PTH?≤?300?pg/mL, calcium <9.5?mg/dL and phosphorus <5.5?mg/dL. Medication use and costs were measured to calculate average costs and incremental cost per responder. Stratification by lower and higher baseline PTH assessed cost per response by disease severity.

Results:

There were 38–77% more responders with cinacalcet vs control, depending on response definition. Mean (SD) per patient total medication costs were $5423 ($3698) for cinacalcet and $2633 ($2334) for control, leading to a mean difference of $2790 over 23 weeks. When response was defined as a decrease in PTH?≥?30% from baseline, the average cost per responder was $11,266 for control vs $7027 for cinacalcet. The incremental cost per incremental responder ranged from $5186–$9168. Across all response measures, cost per responder was lower in patients with lower baseline PTH.

Conclusions:

Representing a more efficient allocation of economic resources over the short-term, cinacalcet-based treatment algorithm led to a lower cost per biochemical response, particularly in patients with lower disease severity, vs vitamin D sterols and phosphate binders alone. These findings should be interpreted alongside the study limitation of converting international trial-based medication utilization into US costs.     

分成制契约下产权制度安排分析

产权制度安排是现代经济学所研究的重点问题之一,不同的产权制度安排对企业的运营效率及整个社会的福利具有重要影响。本文运用委托代理的相关理论,对分成制下的产权制度安排进行了研究。通过对激励约束和参与约束的研究,分析了在分成制契约下产权制度的安排可能存在的问题。提出了在实行承包分成制的契约中,理性的公司不应为经理提供机器设备等工具;在分成制契约下最优的产权制度安排为由公司通过签订长期合同、具体规定设备处理方式及提高提成比率等方法降低经理的风险成本,提高经理的收益等激励措施来鼓励经理购买设备。     

Towards zero deforestation and forest restoration in the Amazon region of Maranhão state,Brazil

The Amazon forest in the state of Maranhão ensures ecosystem services that directly and indirectly affect the life quality of its population and economy, via hydrologic and climatic regulation, among other benefits. Currently, only 25% of the original forest cover (24.7 thousand km²) remains while illegal deforestation persists in a violent process that provokes visible social, economic and environmental harm. Simultaneously, Maranhão has seen record levels of burning, faces a water shortage and fights against the worst social and economic indicators in the country. Conversely, secondary vegetation covers 19.9 thousand km² (27% of deforested area) and is completely unprotected. Contrary to the international commitments assumed by Brazil to combat deforestation and restore forests, some of the political representatives of Maranhão have sought legal mechanisms to further diminish forest cover in public and private areas. To promote the conservation and restoration of Maranhão Amazon Forest, a multi-institutional network of researchers was established in 2015. This viewpoint paper aims to draw attention to this endangered region of the Brazilian Amazon and give science-oriented recommendations to policy makers in order to avoid more setbacks. We argue that Maranhão state must urgently establish a policy of Zero Deforestation, protect secondary forests and comply with the national forest restoration policy, thus ensuring long-term economic sustainability.     

The evolution of Internet interconnection from hierarchy to “Mesh”: Implications for government regulation

The Internet has evolved from a “hierarchy”—in which interconnection was achieved by having Internet Service Providers (ISPs) purchase transit services from top-level backbones and top-level backbone providers engage in direct settlement-free peering—to a “mesh” in which peering occurs among a much larger number of participants and some peering arrangements involve payments from one peer to another. In this new environment, backbone providers, ISPs, and suppliers of content have a far wider array of interconnection alternatives, both technical and financial, than they did only a short time ago. As is often the case, the introduction of new alternatives and contractual arrangements has led to calls to regulate which alternatives and arrangements are acceptable. In this paper, we explain why such regulation would be harmful, as it would (i) reduce the incentives of industry participants to minimize total costs; (ii) lead to higher access prices to end users; (iii) result in prices that do not adequately reflect costs; and (iv) create regulatory inefficiencies. We also explain why the alternative interconnection arrangements to which Content Delivery Networks (CDNs) (and their content provider clients) and ISPs generally have access already impose limits on the exercise of market power, thus obviating any need for regulation.     

Welfare-maximizing assignment of agents to hierarchical positions

We allocate agents to three kinds of hierarchical positions: top, medium, and low. No monetary transfers are allowed. We solve for the incentive-compatible (IC) mechanisms that maximize a family of weighted social welfares that includes utilitarian and Rawlsian welfares. When the market is tough (all agents bear positive risk of obtaining a low position in any IC and feasible mechanism), then the pseudomarket mechanism with equal budgets (PM) and the Boston mechanism without priorities (BM) yield identical assignments which are always optimal. Otherwise, when the market is mild, PM and BM differ and each one implements the optimal rule under different assumptions on the curvature of virtual valuations. We also establish that both BM and PM mechanisms guarantee IC Pareto-optimal assignments for a domain of preference distributions satisfying weak assumptions.     

高职商贸类专业独立实践教学研究——以“项目导入、任务驱动”教学模式为例

通过“项目导入、任务驱动”在独立实践教学模式的运用与研究，探索适应高职商贸类专业的独立实践教学规律，不断提高商贸类专业实践教学的质量，实现高职商贸专业人才的培养目标。